By Dominique Gabriel G. Bañaga
The Philippine Institute of Volcanology and Seismology (Phivolcs) raised the alert level for Mt. Kanlaon to “Alert Level 1” after recording new activity in the area. Based on a bulletin issued at 10:00 a.m. yesterday, the seismic monitoring network at the volcano recorded at least 80 volcanic earthquakes since March 9.
According to Phivolcs, an Alert Level 1 signals a “slight increase in volcanic earthquake and steam/gas activity;” illustrated by a “notable increase in the temperature, acidity, and volcanic gas concentrations of monitored springs.”
In addition, the agency recorded at least 77 “low frequency events associated with magmatic fluids beneath the edifice.” The said increase in seismic activity could potentially be followed by steam-driven, or phreatic, eruptions despite the absence of visible degassing, or steaming, this year.
Ground deformation data gathered from continuous GPS measurements indicate a period of long-term slow inflation since 2017, while short-term electronic tilt monitoring on the southeastern flanks recorded slow inflation of the lower slopes since May 2019 and pronounced inflation of the upper slopes in the end of January 2020.
“These parameters indicate that volcanic processes are underway deep beneath the edifice that may be caused by deep-seated degassing, hydrothermal activity, or magmatic intrusion,” Phivolcs explained.
The agency added, local government units and the public are strongly reminded that entry into the four-kilometer radius Permanent Danger Zone must be strictly prohibited due to the further possibilities of sudden and hazardous eruptions.
Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ejected materials from a sudden phreatic eruption can be hazardous to aircraft./DGB, WDJ